Slide-valve



H-. P. SHAW-.vh

SLIDE VALVE.

Noizgml;

Patented Jan. '22, 1884..

lFig. 1.

"UNirenn-l STATES PATENT @Pereira HENRY F. SHAW, onnosron,MASSACHUSETTS.

' SPECIFICATION forming part of LetterslatentNo, 292,261, dated January22, 1584.7,

Application tiled Junel4, 1853. (No model.)

" yiin the county of Suffolk and State of. Massacl1u setts, haveinventedcertain new and usefulImprovements in Slide-Valves, of which thefollowing is a specification,reference being had i to the accompanyingdrawings.

The-object of `my invention vis toV produce a slide-valve which shall-`provide, atthe instantr of 'opening a Sport, a greater opening for thepassage ofsteam than is done by means of the Ordinary slide-valve, andalso to produce a combined valve adapted for two cylinders havingpistons plying therein in opposite directions, said valvebeingeonstructed to provide, particularly, free and unobstructedexhaust-passages.

My invention consists in so forming thesides `or edges ofthe openings ofthe valve a'nd'valveseat that the open passages will be irregular orzigzag in shape, in distinction from openings having theirlongitudinalsides rectilinear; and, also, in the combination of aB-valve and D-valve joined together to be operated as one valve with thevalve-seat, the valvean'd valve-seat having steam-passages formed andlocated with reference to each other as hereinafter set forth. j

In the drawings, Figures l and 2 are plan views of a valve andvalve-seat embodying my invention, the valve being shown in twodifferent positions on the seat. Fig. 3 is a plan view of the seat, thevalve having been removed. Fig. Il is an outline of the face of thevalve. Fig. 5 is a section of valve and valveseat on line 1 l; and Fig.I6, a section of valve and valve-seat on line 2 2 in Figsa and 4, thevalve beingin the position on the seat as illustrated in Fig. 1. Fig. 7is a diagram for more particular reference hereinafter.

The valve-seatA has a port, a, to lead to one end of one of twocylinders, a port, b, to

lead to the opposite end of the same cylinder, a port, c, leading to oneend of the other ofv the two cylinders, anda port, "d, leading to theopposite end of the latter cylinder. There isa common exhaust port andpassage, e, through the length of the seat. The cylinders are supposedto be located side by side, and the valve and valve-seat over the spacebetween the cylinders, or over the adjoining k.

sides of the saine, the face ofthe seatandvalve being thus brought intoa horizontal plane, Y

/the steam passes from either of the ports aZ and b to the exhaust-porte.- That partof the valve B which corresponds to a B-valve has openingsh and z' in its face, leading to a chamJ-f ber, j, in the valve, throughwhich live steam passes from the steam-chest to the port c, andexhaust-steam from the port c to the exhaust-v porte, and has openings7c and Zin its face,

leading to a chamber, m, in the valve', through which live steam passesfrom the steam-chest to the port d, and exhauststeam from the port d tothe exhaust-port e. Live steam enters the port c above the seat at andopposite the edge n of the valve, and the port b at and opposite theedgeo of thevalve.- Live steam enters the opening It under the valve atand opposite the edge p of the seat, and the opening Z at and oppositethe edge q of the seat. The

inner longitudinal edges and edge faces -of the sides of the ports a andb, opening f, openings h and Z, and outer longitudinal edges and edgefaces of the sides of the ports c and cl are.4

grooved, whereby there are formed grooves fr and projections s at theabove-named edges and edge faces of the valve, and grooves t andprojections u at the named edges and edge faces of the valve-seat. Saidedges are at the sides of the passages formed in the working of thevalve for the eXhaust-steamto the chambers in the valve. valve isopposite a groove in the seat, and consequently each projection on theseat is opposite a groove in the valve, and the projections vand grooveshave a like contour, so that an opening between two edges so formed hasa shape represented at o in Fig. 7. 'Through such an opening, especiallywhen the zigzag passage is of slight width, as it is at the commencementof making the same, I believe more steam will pass than through astraight passage-that is, one having rectilinear sides.

I do not confine this part of my invention to anyparticular form ofprojections and grooves,

Each projection on the' IOO degree Whatever the form ol projections andgrooves may be, provided they correspond to each other. s

In the drawings is illustrated provision for this irregular or zigzagpassage for the exhaust only; but such may also be employed for the livesteam.

It will be seen that when the exhaust-steam is about to be admitted toeither` of the chambers j and m, and either of the ports c and d isabout to be opened, the corresponding opening, t' or k, in the valve isWell over the exhaust-port e. This is an important feature in myinvention, since the :flow of the exhauststeain is not retarded,as itwould be were the passages from said chambers to the commonexhaust-port, e, opened at the same time that the ports c and d wereopened.` By this arrangement of the passages and construct-ion of thispart of the Valve, as shown, I provide for ample lead7 in the part ofthevalve corresponding to a B-valvc for the exhaust-steam, and Very freepassage for the egress of the same.

I claim as my invention- 1. In aslide-valve and seat therefor,openingsthe sides ofwhiehhave projections and grooves i`11 their edges or edgefaces, whereby one or more passages across the plane of contact of valveand valve-seat are irregular or zigzag in shape, substantially asspecified.

2. In combination with the chambers j and m, openings h i and LZ in theValve, and ports c, d, and e in the seat, said openings and port-s beingso located with reference to each other that either of the openings t'and 7c is well over the port e when that one of the openings 7L and lleading to the same chamber is about to enter upon the corresponding oneot' the portsc and d, substantially as shown and specified.

3. A valve consisting of two parts, one of said parts corresponding to aD-valve, and the other of said parts corresponding to a B- valve, theedges of passages and ports presenting projections and grooves, toprovide one or more passages across the plane of contact of valve andvalveseat of an irregular or zigzag shape, as set forth. I

4. A. valve, being a combination of a D- val ve and a B-Yalve, theopenings iu that part of which' that corresponds to a B-valve and theports in the seat therefor are located in such relation to each otherthat when the opening leading from either of the two chambers is wellover the common exhaust-port in the seat the port leading from the seatto the saine chamber in the valve is about to be opened, substantiallyas and for the purpose set forth.

HENRY Ff SHAW.

Witnesses:

GEO. R. Gorcnox, EDW. Dumme.

